Rock drill



Mamhl 193@ E. F1 TERRY 2,034,122

ROCK DRILL Filed OCT.. lO, 1934 HLS'A TTORNEY.

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Patented Mar. 17, 1936 UNITED STATES PATENT OFFICE ROCK DRILLApplication October 10, 1934, Serial No. 747,722

2 Claims. (Cl. 121-1) This invention relates to rock drills, and moreparticularly to a valve chest construction for rock drills of the fluidactuated type.

One object of the invention is to enable the valve chest parts to beassembled and disassembled With a minimum expenditure of time.

Other objects Will be in part obvious and in part pointed outhereinafter.

In the accompanying drawing illustrating the invention and a practicalapplication thereof,

Figure 1 is a plan View of a rock drill constructed in accordance withthe practice of the invention,

Figure 2 is a transverse View through Figure 1 on the line 2-2, and

Figure 3 is a transverse View taken through Figure 2 on the line 3-3.

Referring more particularly to the drawing, designates, in general, arock drill comprising a cylinder 2l and a valve chest 22 which, for thesake of simplicity of illustration, is shown as being an integral partof the cylinder 2|.

The valve chest may be of a conventional type having a bore 23 extendingentirely therethrough to constitute a receptacle for the distributingvalve mechanism comprising a pair of bushings 24 the interior of whichserve as a valve chamber 25 for the accommodation of a distributingvalve 26.

The valve 26 is of the spool type reciprocable in the valve chamber 25for controlling the distribution of pressure fluid to the opposedpressure surfaces of a piston 2l in the cylinder 2|. The ends of thevalve chamber 25 are sealed by imperforate closures 28 Which extendslidably part way into the bushings 24 and have flanges 29 that seatagainst the outer ends of the bushings 24.

In accordance with the practice of the invention means are provided forsecuring the closures 28 firmly in assembled position in the ends of thevalve chamber. The means illustrated comprises an endless yoke 30 whichencircles the valve chest, in a horizontal plane, and is held againstrotary movement by a raised portion 3l on the exterior of the valvechest which engages intermediate portions of the inner surface of theyoke.

As a preferred form of construction one of the closures 28 is providedwith a trunnion 32 of which the end is rounded and extends into adepression 33 in the inner surface of the yoke. In

the opposite end of the yoke is a set screw 34 having a ball end 35which extends into a depression 36 in the outer end of the adjacentclosure 29.

In practice, Whenever it is desired to disassemble the valve mechanismthe screw 34 is unthreaded to remove its rounded end from the depression36. The yoke may then be lifted from the closures 28 and the closuresmay be removed from the ends of the valve chamber to permit access tothe bushings 24 and the valve 26. As Will be readily appreciated, thisoperation of disassembling the valve mechanism may be per.- formedquickly since it requires the manipulation of only the one screw 34.

A further advantage of the present invention is that by securing theclosures 28 in sealing position by means of a yoke disposed exteriorlyof the valve chest, as distinguished from structures wherein theclosures are held by a bolt or rod extending through the valve, thediameters of the various portions ofthe valve, and therefore of thevalve chest may be held to small dimensions.

I claim:

l. In a rock drill, the combination of a casing having a chamber andclosures inserted slidably into the ends of the chamber to seal saidchamber, a retaining device exteriorly of the casing freely detachablefrom and acting against both closures to hold them in sealingrelationship with the casing, and a portion on the yoke engaging thecasing to prevent rotary movement of the yoke with respect to thecasing.

2. In a rock drill, the combination of a casing having a chamber andimperforate closures inserted slidably into the ends of the chamber toseal said chamber, a retaining device exteriorly of the casing forlocking the closures in sealing position having portions interlockinglyengaging the closures and being freely removable from the closures, andportions on the yoke engaginglthe casing to prevent rotary movement ofthe yoke with respect to the casing.

EDWARD F. TERRY.

